BirdAnalyst
Species · South Carolina · BBS 2025 Release · 1966–2024

Brown-headed Cowbird Population Trend in South Carolina

All statesGeneralists

Brown-headed Cowbird in South Carolina has surged: up 565% on the route-weighted index since 1968.

+565%Since 1968
50Routes In State
57Years

Notable Brown-headed Cowbird Trends in South Carolina

long arc increasecomputed index

Brown-headed Cowbird has surged in South Carolina: up 565% on the route-weighted index since 1968.

Brown-headed Cowbird Population Forecast in South Carolina

If the recent trend holds, Brown-headed Cowbird in South Carolina is projected to rise about 26% by 2029 — from 5.0 in 2024 to a central estimate of 6.3 (95% range 3.2–9.5). A 5-year backtest shows a typical error of ±27.6%, with 100% of held-out values landing inside the 95% band.

+26%Change by 2029
6.3Projected 2029 index
3.2–9.595% range
±27.6%Backtest error
19662029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20256.13.09.3
20266.23.19.3
20276.23.19.4
20286.33.29.4
20296.33.29.5

Brown-headed Cowbird Survey Routes in South Carolina

Routes recording Brown-headed Cowbird in South Carolina.
Holly Hill1920241972
Little Mtn1519881977
Pinewood1520191998
Bennettsville1420171998
New Holland1320241970
Campobello1320242010
Kingstree1120102010
Green Sea1020242010
Blacksburg920111998
Owings 2920242005
Dillon820211973
Pendleton819761966
Joanna820231999
Chesnee820151992
Rome720241974
Carvers Bay720121998
Nixonville619951987
Prosperity620241992
Adams Run520241988
Sandhills420241995
Walterboro420171970
Boiling Spgs419791970
Plum Branch420241977
New Ellenton420242010
Whitmire420232010

Brown-headed Cowbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.